[PATCH] ARM: VIC: use irq_domain_add_simple()

On Thu, 20 Dec 2012 19:45:24 +0100, Linus Walleij [off-list ref] wrote:

On Wed, Dec 19, 2012 at 12:34 AM, Grant Likely
[off-list ref] wrote:

quoted

It looks to me like the below patch breaks versatile because it makes
it try to register a linear irq_domain instead of the legacy one that
it needs. Here are the relevant commits:

07c9249f1: "ARM: 7554/1: VIC: use irq_domain_add_simple()"
946c59a08: "ARM: vic: fix build warning caused by previous commit"

(sorry for the really late reply on this. I took a break at Christmas
and jetlag has been beating up my concentration since I got back. I
actually started writing this reply before Christmas, but the
investigation sidetracked me enough that I never finished it.)

quoted

I'm working on getting it properly sorted out (and more importantly
*simplified*), but in the mean time I think the above two commits need
to be reverted. Reverting them on my tree fixes booting for me.

Isn't that a bit violent, can't we just fix the real bug?

I did try to fix the bug first, but it became more involved that I would
like for a stablization change (and I went down a lot of rabbit trails
in the process). I preferred reverting because this was all contained
to a single driver which can be backed out easily to have another cycle
for a correct fix. I did try your change though...

Does the below patch work for you, it does two things:

1) Bump all Versatile IRQs to offset at 32, because it is using
  IRQ 0 which is NO_IRQ and illegal anyway so it's anyway
  a bug that should be fixed.

2) Make sure we call irq_create_mapping() if the start IRQ is
  anyway 0, as in the device tree case, and make sure to
  actually pass zero in that case.

In actual fact, only changing the offset to 32 is required to get
Versatile to boot with DT. That platform doesn't yet use vic_of_init().
It currently depends on pre-allocated irq_descs. Calling
irq_create_mapping() doesn't resolve this. I now have patches to rework
the versatile OF support to use irq_of_init(), but they aren't ready
for posting yet. Merging the bump to offset 32 would be fine for now.

Since you're touching this line anyway, please change to:

#define IRQ_SIC_START			(IRQ_VIC_START + 32)

Similarly here: #define IRQ_SIC_END (IRQ_SIC_START + 31)

And then you can add my acked by for the irq number changes.

Acked-by: Grant Likely <redacted>

g.